The invention described herein is generally related to diamond-anvil high-pressure cells used for high pressure studies, and is also generally related to X-ray collimators such as are used in X-ray diffraction equipment and for other purposes. This invention is the result of a contract with the U.S. Department of Energy (Contract No. W-7405-ENG-36).
Diamond-anvil high-pressure cells are well-known devices which are used to study materials at high static pressures. In a typical diamond-anvil cell, two brilliant-cut diamonds, each with its culet point truncated to form a planar face, are compressed in opposition against one another. A deformable metal gasket, consisting of a flat piece of metal foil with a small hole in it, is placed between the opposing diamond faces, with the sample to be studied being contained in the hole in the foil and between the opposing diamond faces. Static pressures on the order of 600 kilobars can be readily obtained by mechanical compression of the diamonds. The primary advantage of the diamond-anvil cell is that the sample can be viewed through the two optically transparent diamonds, thus enabling spectroscopic and other optical studies to be conducted while the sample is compressed.
X-ray diffraction studies are a principal use of diamond-anvil cells. In preparation for such studies an X-ray beam must be highly collimated and directed so as to pass through the two diamonds and the sample contained between them. The X-ray beam is ordinarily collimated by means of an elongate tubular metal collimator. Such collimators have very small diameter bores in order to narrowly collimate the X-rays prior to passage through the faces of the opposed diamonds and the sample. With previously known diamond-anvil cells, the alignment of the X-ray collimator has been a difficult and time-consuming task, sometimes requiring an entire day to perform. Moreover, it has previously been impossible to remove the collimator, once it has been aligned, and replace it without having to repeat the alignment process. Nevertheless, it is sometimes necessary to remove the collimator temporarily while a sample is under pressure, in order to inspect the sample or for other purposes. Thus, in X-ray diffraction studies a great deal of time has been involved in the alignment and realignment of the X-ray collimator.